298 >NTBIBUTI0N8 PROM mm NATIONAL HEBBABIT7M. 



BIDDULPHIA S. F. Gray. 



- r Gray, Nat. Air. I: 294 1821. Van Heur. Synop. 

 i Ig. Consp. Crit. Dial Kttl Bw ill. 137 pi. U \ I /// / ;. 



L844. 



Qb. Phys. A Mi. Akad. Wiss. Berl. 1839: i:;i. L60. pi. ',. /. n i :. L841; 

 M ikr. g.pl. ■•• .!. A A 'III./ 17. 1864. Bail. Am. Journ. Sci. 46: 138. 1844. 

 Amphitetraa Ehrenb. in part; Phys. Abh. Akad. Wiss. Berl. 1839: L22, 111'. L841. 

 Km; . Bacill. 135. pi 19 . L844. 



■ miiis Ehrenb. in part; Ralfs in Pritch. Hist. (nfus. ed. 4. 847. 1861. Cleve, 

 Journ. Quek. Mi.-r. Club 11. 2: L71. L885. Pant. Beitr. Bacill. CJng. 2: 97. L889; 3: 

 pi L893. 



Ehrenb. PhyB. Abh. Akad. Wiss. Berl. 1839: 129, L50. pi 4. /. W. 

 L841,inpart. Eloper, Quart. Journ. Micr. Sci. 2: 283./. 1. L854. Bright. 4: 274. 

 pi 17. /. 9 It. L856. 

 Denticella Ehrenb.; Ehrenb. in Ber. Akad. Wias. Berl. 1840: 207. L841. Grun. 



Denkschr. Akad. Wien48 3 : 59. L884. 

 Odontotropis Grun.; in part, DeToni, Syll. Alg. 2: 881. L894. 

 In including the above genera, wholly or in part, in Biddulphia a generic unity u 

 attained thai ia most desirable. This facl has long been appreciated l>y most diato- 

 mist8, and the Bynonymy here enumerated is essenl ially thai oi < rrunow, Van Beurck, 

 Brun, Win. Boyer, etc. A careful Btudy of these forms convinces note thai the plan 

 adopted in De Toni's Sylloge Algarum of reestablishing Odontella, Zygoceros, Denti- 

 cella, and 1 terataulusas independenl genera is unwise. No Bel of distinguishing charac- 

 teristics importanl and constanl enough to serve as generic definitions can be found for 

 aames. Although this will become sufficiently evidenl in considering the sepa- 

 rate species following, an illustration <>r two may be here mentioned For example, a 

 comparison of Odontella obtusa Kiitx.." with Biddulphia roperiana Grev.,6 and of these 

 two with ( 'erataulus galapagt nsis Schmidt, < will make ii clear how futile i1 is to attempt 

 to make generic distinctions between these three diatoms. The genus Zygoc 

 deservedly obsolete; compare /. radiatus Bail.d with Biddulphia balaena (Ehrenb.) 

 Bright.* Amphitetraa might be blended with thai unscientific complex '"fticera- 

 tium," a genus made up chiefly of evidenl forms of Biddulphia, bul in its general 

 structure, in the markings and processes of the valves, and in the zigzag, chain-like 

 growth of its members ii is so typical a Biddulphia thai the example of Van Beurck, 

 Boyer, and others, in classing mosl of its species as Biddulphia certainly dec 

 imitation. The genus Triceratium is chiefly made up of biddulphoid forms, which 

 arc here classed in this genus. A lull discussion of the relationship between Biddul- 

 phia and Triceratium will be given under the genus Trigonium. See also remarks 

 under the genera Aulacodiscus and Porpeia. 



Biddulphia alaskiensis Mann. >p. nov. PLATB XI. VI. noURE 1. 



Valve broadly oval, nearly circular, evenly and strongly convex, the two proc- 



barely elevated above the surface of the valve; markings of minute and purely 



radial beading, there being, however, a slighl curvature <>i' the lines toward the sides 



of the two processes; a few minute spines scattered irregularly over the sun, 



"Kin/. Bacill. pi. 18. VIII. f. 1 -.'. L844; or Van Beur. Synop. pi. 100. /. 11 14. 

 L881. 



Man Heur. Synop. pi 99./. 4-6. 188h Trans. Aficr. Soc. Lond. u. s. 7: />!. 8./. 

 ii 18. L859. 



Schmidt, Atlas pi. 115. f. 8. L888. 



dSmithson. Contr.'Knowl. 7: pi i.f. 19. L864. 



e Quart. Journ. Micr. Sci. 7i.pl 9./. 15. 1869; or Van Heur. Synop. pi. 112./. i. L887, 



